Eye position under general anesthesia in orthophoric children

Purpose The aim of this study is to evaluate the effect of general anesthesia with muscle relaxant on the horizontal ocular deviation in orthophoric children. Methods Children aged 4–16 years requiring a non-ophthalmological surgical procedure under general anesthesia with neuromuscular blockade were included. Prior ophthalmological examination excluded any oculomotor disorder. Horizontal ocular deviation was measured by the Hirschberg photographic method by comparing pictures taken in the awakened state to those taken under general anesthesia. Monitoring of anesthesia was performed by the Bispectral index (BIS) and muscle relaxation by the train of four (TOF). Results 33 Patients were included. Mean age was 8(±4) years and 67.7% were male. The mean horizontal ocular deviation after general anesthesia with neuromuscular blockade was −0.2 diopters (SD 9.7). Median was −0.7 diopters. 72.7% of patients had an ocular deviation of less than 7.5 diopters with a normal distribution. Conclusions Our results show that contrary to popular belief, eye position under general anesthesia in children without strabismus is not divergent but very close to orthophoria.